Mass storage systems are used to store large amounts of data. Important parameters of such devices include speed and reliability. The systems preferably operate without error for long uninterrupted periods of time. To accomplish this, the systems store system data in addition to user data. The system data may be used to recover user data which is lost because of, for example, a power failure or a hardware failure.
Some systems use RAID (redundant array of independent disks) technology. RAID technology uses multiple memory components to form a single logical memory storage unit. The stored data is distributed among the memory components, and includes the system data for data recovery. Depending upon what level of RAID technology is used, the system may be able to recover from multiple errors. For example, RAID technology allows for recovery from multiple errors. For example, RAID6 technology allows for recovery from two errors.